In recent years, the number of patients with allergic diseases such as bronchial asthma, pollinosis in adults and atopic dermatitis in children has been increasing, and these diseases have become a significant social problem. Currently one out of three people have some form of allergy, and allergies are even being referred to as a national disease. In general, there are four types of allergic reactions, which are anaphylaxis (type I), cytotoxic type (type II), alsas type (type III) and cell-mediated type (delayed type) (type IV). Pollinosis, which has particularly been an issue recently, is classified as a type I allergy. Also, atopic dermatitis is thought to be primarily due to a type I allergy reaction.
In type I allergies, IgE antibody, which is produced due to invasion of an allergen (antigen), binds to the Fc receptors on fat cells, and when a reinvading antigen binds to this IgE, chemical mediators (chemical substances) such as histamine and leukotriene are released from granules of the fat cells, which in turn either directly or indirectly cause an acute inflammatory reaction accompanied by symptoms such as asthma, rhinitis, sneezing, runny nose and itchy eyes. Thus, shutting down any of the above pathways could be effective in order to prevent type I allergic reactions.
Conventionally, extensive research has been conducted on pharmaceutical components having antiallergic action, and numbers of synthetic compounds have been reported to have such antiallergic action. For example, components with an activity to inhibit the release of histamine from fat cells or components with an activity to inhibit the release of leukotriene from macrophages (also referred to as leukotriene production inhibitory activity) can be expected to serve as antiallergic agents. However, there have been very few naturally occurring substances known to have an antiallergic activity. Moreover, there have been hardly any naturally occurring substances obtained that are safe and have an adequate antiallergic activity. Consequently, in the field of medicine in particular, there have been needs to search for compounds having an adequate antiallergic activity and to develop antiallergic agents.
The object of the present invention is to provide novel antiallergic agents, medicaments, foods, drinks or cosmetics comprising the same, and a process for producing the same.
The present inventors have conducted extensive and intensive studies to search for novel antiallergic agents by using histamine-release inhibitory activity as an indicator of efficacy in the treatment of allergic diseases. As a result, it was found that tomatoes contain components having an antiallergic activity, and that a fraction having an antiallergic activity is mainly contained in pericarps of tomatoes. In addition, the present inventors also found that the above fraction having an antiallergic activity consists of naringenin chalcone and the caffeic acid derivatives including tricaffeoylquinic acid and dicaffeoylsuccinylquinic acid, that these have histamine-release inhibitory activity, and that they are useful as antiallergic agents. Moreover, the antiallergic activity of these compounds was found to be more potent than that of other caffeic acid derivatives (such as caffeic acid or dicaffeoylquinic acid) known to have said activity.